| Name | Keuffel & Esser 4065 T Duplex Trig |
| Front Scales | A = B S C = D |
| Back Scales | A = BI T CI = D ] L |
| Type of Rule | slide rule |
| Material | Engine divided celluloid laminated mahogany |
| Dimension (mm) | |
| Area of Use | generic |
| Origin of Rule | Michael O'Leary |
| Match Number | 4174 |
| Comment | |
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